bump.h

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/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
 *
 * SPDX-License-Identifier: Apache-2.0 */
 
#pragma once
 
#include "kernel/globals.h"
 
#include "kernel/geom/attribute.h"
#include "kernel/geom/object.h"
#include "kernel/geom/primitive.h"
 
#include "kernel/svm/util.h"
 
#include "kernel/util/differential.h"
 
CCL_NAMESPACE_BEGIN
 
/* Bump Eval Nodes */
 
ccl_device_noinline void svm_node_enter_bump_eval(KernelGlobals kg,
                                                  ccl_private ShaderData *sd,
                                                  ccl_private float *stack,
                                                  const uint offset)
{
  /* save state */
  stack_store_float3(stack, offset + 0, sd->P);
  stack_store_float(stack, offset + 3, sd->dP);
 
  /* set state as if undisplaced */
  const AttributeDescriptor desc = find_attribute(kg, sd, ATTR_STD_POSITION_UNDISPLACED);
 
  if (desc.offset != ATTR_STD_NOT_FOUND) {
    differential3 dP;
    float3 P = primitive_surface_attribute<float3>(kg, sd, desc, &dP.dx, &dP.dy);
 
    object_position_transform(kg, sd, &P);
    object_dir_transform(kg, sd, &dP.dx);
    object_dir_transform(kg, sd, &dP.dy);
 
    sd->P = P;
    sd->dP = differential_make_compact(dP);
 
    /* Save the full differential, the compact form isn't enough for svm_node_set_bump. */
    stack_store_float3(stack, offset + 4, dP.dx);
    stack_store_float3(stack, offset + 7, dP.dy);
  }
}
 
ccl_device_noinline void svm_node_leave_bump_eval(KernelGlobals kg,
                                                  ccl_private ShaderData *sd,
                                                  ccl_private float *stack,
                                                  const uint offset)
{
  /* restore state */
  sd->P = stack_load_float3(stack, offset + 0);
  sd->dP = stack_load_float(stack, offset + 3);
}
 
CCL_NAMESPACE_END